1. Field of the Invention
This invention relates to an optical measuring apparatus having an optical system capable of focusing on a object mounted on a table to project a picture image of the object on a screen and a measuring method thereof and, more particularly, to an apparatus and a measuring method thereof wherein the object mounted on the table is illuminated and wherein a projector having an optical system to focus on the object to project an optical picture image of the measuring object on the screen is provided to measure the dimensions and shape of the object with a relative movement of the optical system and the measuring object.
2. Description of the Related Art
A so-called CNC projector, a projector which has previously been used, is adapted to move the optical system to project an optical picture image of a measuring object on a screen and a table to mount thereon the measuring object, relatively based upon a prepared measuring program thus to incorporate the relative movement value when an edge of the picture image is detected by an edge detecting Sensor to obtain the dimensions and the shape of the object.
To prepare of the measuring program for controlling the relative movement between the optical system and the table the CNC projector has been conducted by directly shifting the table on which the measuring object is mounted so that several measuring points coincide with a reticule, focus lines formed on the screen, or by inputting position data of the individual measuring points by means of a keyboard of the computer in the light of a specifications showing the measuring object.
This former system is disadvantageous in view of a working efficiency as the table should be shifted so that the measuring points precisely coincide with the reticle shown on the screen. The fine allocation of the table by different operators, each naturally having different skill in measurement, may influence a measuring accuracy.
The current system is also disadvantageous to attain reduced time of the measuring procedure since each of the position data of the measuring points should be inputted through the keyboard in the light of the specifications showing the measuring object, which may require certain ability to operate the keyboard to thereby disturb popularity of the CNC projector.
The present invention aims to provide a desirable optical measuring apparatus and a measuring method thereof so that the above mentioned disadvantages can be solved and anyone can designate the measuring points simply and instantly.